Try to connect to home router we get very low signal (-90dBm) while standing next to the router.
Ant known problem with the antenna?
Also the BLE signal is very weak compare to the NANO 33 BLE ??
Has the antenna been damaged in any way? What's the signal like if you are 10m away?
No damage to the antennas.
From 10 m there is no signal detected.
From 50 cm the signal is -85dBM
You didn't say what it is. 
Arduino rp2040 connect
Okay, are there any objects near the board? Prototype circuits? Modules? Case?
No. Connect directly with usb cable to the pc
Try a different access point.
Also done , with smartphone hot spot. Same performance
Is it sitting on a table? What is the table made of? By the way, if you have already done any troubleshooting steps, please list them here so we have the benefit of the information and don't have to waste time asking...
Table from wood
Well, you might have a faulty board...
It's under the category of " [Nano RP2040 Connect]" 
But I have two of them. Same problem. Bought in deferent orders??
Can you try connecting to another computer (in case there is electrical noise on the one you are connected to which is causing an issue).?
Can you try changing the channel on the WAP?
Have you tried updating the WiFiNINA firmware?
There are so many users posting in the wrong forums, I hardly even look there.
Tried on two deferent computers.
The wifinina firmware was updated to latest version 1.48
Those tiny ceramic antennas are not great.
It looks from metal, not ceramic
Have good experience with the Arduino nano ble . The BLE connection and signal is much better than the BLE signal of the rp2040